Process for preparing benzothiophenecarboxamide derivatives

Abstract

A process for preparing a compound having PGD 2 antagonism represented by the formula (I), or a pharmaceutically acceptable salt or hydrate thereof, which process comprises reacting an amino alcohol of the formula (II) or its salt with a compound of the formula (III) or its reactive derivative, oxidizing the product with halo oxoacid in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyls, reacting the product with an ylide under the conditions for Wittig reaction, and optionally deprotecting the product.

What is claimed is:  
     
       1. A process for preparing an amino alcohol of formula (II):                    
       or a salt thereof, which comprises reducing a compound of formula (II-2):                    
       wherein R 2  is alkyl and R 3  is hydrogen or alkyl, with a reducing agent-Lewis acid system.